The present invention relates to novel ophthalmic solutions that contain a ethoxylated glyceride as an additive to improve the wettability and to decrease the degree of protein and polymeric preservative binding to contact lens surfaces. These compositions may also comprise other agents in contact lens and ophthalmic solutions such as buffers, tonicity agents, wetting agents, enzymes, hydrogen peroxide, demulcents, thickeners, sequestering agents (chelating agents), surface active agents and preservative agents. The ethoxylated glycerides are particularly useful in contact lens treatment solutions, contact lens wetting solutions, solutions used to store contact lenses and solutions used to clean or rinse contact lenses. It has been found that surprisingly the addition of ethoxylated glycerides improve the comfort of lenses treated with such solution and that this increased comfort is surprisingly long-lasting in its effect. The ethoxylated glycerides may be mono-, di- or triglycerides.
The solutions of the present invention are made by one of two methods. First the ethoxylated glyceride may be melted and added to an aqueous solution which includes the other agents to be used in the desired formulation, or the additional agents may be added prior to the addition of the melted ethoxylated glyceride. Second, the ethoxylated glyceride may be dissolved in an alcohol base and this liquid mixture, added to the aqueous base. Ethoxylated glycerides are commercially available from numerous commercial sources and include Polyoxyl 40 hydrogenated castor oil (Cremophor® RH 40), polyoxyl 60 hydrogenated castor oil (Cremophor® RH 60), polyethyleneglycol (“PEG”) 30 Castor Oil (Incrocas® 30), PEG-35 Castor Oil (Cremophor® EL Incrocas® 35), or PEG-40 Castor Oil (Cremophor® EL Incrocas® 40), Cremophor® EL®, Emulphor® EL®, glycerol polyethyleneglycol riciinoleate, gycerol polyethyleneglycol oxystearate, polyethoxylated hydrogenated castor oil, or polyethoxylated vegetable oil. The ethoxylated glycerides useful in the present invention may include surfactants sold as PEG-6 Caprylic/Capric Glycerides PEG-8 Caprylic/Capric Glycerides; PEG-2 Castor Oil; PEG-3 Castor Oil; PEG-4 Castor Oil; PEG-5 Castor Oil; PEG-8 Castor Oil; PEG-9 Castor Oil; PEG-10 Castor Oil; PEG-11 Castor Oil; PEG-15 Castor Oil; PEG-20 Castor Oil; PEG-25 Castor Oil; PEG-30 Castor Oil; PEG-33 Castor Oil; PEG-35 Castor Oil; PEG-36 Castor Oil; PEG-40 Castor Oil; PEG-50 Castor Oil; PEG-54 Castor Oil; PEG-55 Castor Oil; PEG-60 Castor Oil; PEG-100 Castor Oil; PEG-200 Castor Oil; PEG-18 Castor Oil Dioleate; PEG-60 Corn Glycerides; PEG-20 Evening Primrose Glycerides; PEG-60 Evening Primrose Glycerides; PEG-7 Glyceryl Cocoate; PEG-30 Glyceryl Cocoate; PEG-78 Glyceryl Cocoate; PEG-80 Glyceryl Cocoate; PEG-12 Glyceryl Dioleate; PEG-15 Glyceryl Isostearate; PEG-20 Glyceryl Isostearate; PEG-30 Glyceryl Isostearate; PEG-60 Glyceryl Isostearate; PEG-12 Glyceryl Laurate; PEG-20 Glyceryl Laurate; PEG-23 Glyceryl Laurate; PEG-30 Glyceryl Laurate; PEG-10 Glyceryl Oleate; PEG-15 Glyceryl Oleate; PEG-30 Glyceryl Oleate; PEG-20 Glyceryl Ricinoleate; PEG-5 Glyceryl Sesquioleate; PEG-5 Glyceryl Stearate; PEG-10 Glyceryl Stearate; PEG-25 Glyceryl Stearate; PEG-30 Glyceryl Stearate; PEG-120 Glyceryl Stearate; PEG-200 Glyceryl Stearate; PEG-28 Glyceryl Tallowate; PEG-80 Glyceryl Tallowate; PEG-200 Glyceryl Tallowate; PEG-5 Glyceryl Triisostearate; PEG-5 Hydrogenated Castor Oil; PEG-7 Hydrogenated Castor Oil; PEG-16 Hydrogenated Castor Oil; PEG-20 Hydrogenated Castor Oil; PEG-25 Hydrogenate Castor Oil; PEG-30 Hydrogenate Castor Oil; PEG-35 Hydrogenate Castor Oil; PEG-40 Hydrogenate Castor Oil; PEG-45 Hydrogenate Castor Oil; PEG-50 Hydrogenate Castor Oil; PEG-54 Hydrogenate Castor Oil; PEG-55 Hydrogenate Castor Oil; PEG-60 Hydrogenate Castor Oil; PEG-80 Hydrogenate Castor Oil; PEG-100 Hydrogenate Castor Oil; PEG-200 Hydrogenate Castor Oil; PEG-40 Hydrogenated Castor Oil PCA Isosterate; PEG-5 Hydrogenated Corn Glycerides; and PEG-8 Hydrogenated Fish Glycerides; which are all available from known commercial sources.
The solutions of the present invention may contain other additives including but not limited to buffers, tonicity agents, demulcents, wetting agents, preservatives, sequestering agents (chelating agents), surface active agents, and enzymes.
Other aspects of the claimed solutions include adding to the solution from 0.001 to 1 weight percent chelating agent (preferably disodium EDTA) and/or additional microbicide, (preferably 0.00001 to 0.1 or 0.00001 to 0.01) weight percent polyhexamethylene biquanide N-alkyl-2-pyrrolidone, chlorhexidine, polyquatemium-1, hexetidine, bronopol, alexidine, low concentrations of hydrogen peroxide, and opthalmologically acceptable salts thereof.
Ophthalmologically acceptable chelating agents useful in the present invention include amino carboxylic acid compounds or water-soluble salts thereof, including ethylenediaminetetraacetic acid, nitrilotriacetic acid, diethylenetriamine pentaacetic acid, hydroxyethylethylenediaminetriacetic acid, 1,2-diaminocyclohexanetetraacetic acid, ethylene glycol bis (beta-aminoethyl ether) in N,N,N′,N′ tetraacetic acid (EGTA), aminodiacetic acid and hydroxyethylamino diacetic acid. These acids can be used in the form of their water soluble salts, particularly their alkali metal salts. Especially preferred chelating agents are the di-, tri- and tetra-sodium salts of ethylenediaminetetraacetic acid (EDTA), most preferably disodium EDTA (Disodium Edetate).
Other chelating agents such as citrates and polyphosphates can also be used in the present invention. The citrates which can be used in the present invention include citric acid and its mono-, di-, and tri-alkaline metal salts. The polyphosphates which can be used include pyrophosphates, triphosphates, tetraphosphates, trimetaphosphates, tetrametaphosphates, as well as more highly condensed phosphates in the form of the neutral or acidic alkali metal salts such as the sodium and potassium salts as well as the ammonium salt.
The pH of the solutions should be adjusted to be compatible with the eye and the contact lens, such as between 6.0 to 8.0, preferably between 6.8 to 7.8 or between 7.0 to 7.6. Significant deviations from neutral (pH 7.3) will cause changes in the physical parameters (i.e. diameter) in some contact lenses. Low pH (pH less than 5.5) can cause burning and stinging of the eyes, while very low or very high pH (less than 3.0 or greater than 10) can cause ocular damage.
The additional preservatives employed in the present invention are known, such as polyhexamethylene biguanide, N-alkyl-2-pyrrolidone, chlorhexidine, polyhexamethylenebiguanide, alexidine, polyquatemium-1, hexetidine, bronopol and a very low concentration of hydrogen peroxide, e.g., 30 to 200 ppm.
The solutions of the invention are compatible with both rigid gas permeable and hydrophilic contact lenses during storage, cleaning, wetting, soaking, rinsing and disinfection.
A typical aqueous solution of the present invention may contain additional ingredients which would not affect the basic and novel characteristics of the active ingredients described earlier, such as tonicity agents, surfactants and viscosity inducing agents, which may aid in either the lens cleaning or in providing lubrication to the eye. Suitable tonicity agents include sodium chloride, potassium chloride, glycerol or mixtures thereof The tonicity of the solution is typically adjusted to approximately 240-310 milliosmoles per kilogram solution (mOsm/kg) to render the solution compatible with ocular tissue and with hydrophilic contact lenses. In one embodiment, the solution contains 0.01 to 0.5 weight percent sodium chloride.
Suitable viscosity inducing agents can include lecithin or the cellulose derivatives such as hydroxymethylcellulose, hydroxypropylcellulose and methylcellulose in amounts similar to those for surfactants, above.